Optimal feeding frequency of captive head-started green turtles (Chelonia mydas)

Optimal feeding frequency was investigated to improve head-started propagation programme of juvenile green turtles (Chelonia mydas). The 15-day-old turtles (25-26 g body weight) were fed for ad libitum intake at one (1MD), two (2MD), three (3MD) or four (4MD) meals daily over a 3-month trial. Responses in growth, feed utilization, faecal characteristics, haematological parameters and carapace elemental composition were used to compare treatment effects. At the end of the feeding trial, no treatment had induced mortality. Growth performance in terms of weight gain and specific growth rate was similar in turtles fed 2MD, 3MD or 4MD (p > 0.05), but 1MD differed from these (p < 0.05), and feeding at excess frequency (3MD and 4MD) increased the within-group size variation. Turtles fed 2MD had significantly lower feed intake than in 3MD and 4MD groups, but the feed conversion ratios were similar. Faecal digestive enzyme analysis indicated higher catabolism of lipid and protein in the deprivation group (1MD), when compared with turtles fed at least twice daily. The feeding frequency did not affect the specific activities of carbohydrate-digesting enzymes. The results on enzymes activities were corroborated by the transition enthalpy characteristics of faeces, indicating nutrients remaining after digestion. The 2MD treatment also improved the haematological characteristics and the carapace quality, relative to low or excess feeding. Overall, the findings indicate that feeding juvenile green turtles twice a day is the preferred option in their head-started propagation. This promotes growth, reduces feed consumption, and improves health and carapace quality.